A colloidal gold immunochromatography for the detection of flumioxazin residues in fruits

In this study, an excellent monoclonal antibody (mAb) was produced that could sensitively and specifically recognize Flu in fruit samples. The mAb belonged to the IgG2 subclass and had a half-inhibitory concentration (IC50) of 0.59 ng/ml and a limit of detection (LOD) of 0.13 ng/ml. A cross-reactivity test revealed that the mAb had good specificity for Flu. A gold nanoparticle-based lateral-flow immunochromatographic (ICA) strip was used for the rapid screening of Flu in fruit samples. The method had a visual cut-off value of 10 mu g/kg for Flu in three different fruit samples when evaluated with the naked eye. The LODs were 5.25, 3.13, and 4.64 mu g/kg for Flu in apples, grapes, and oranges, respectively, as obtained with the aid of a strip scan reader. Therefore, this ICA strip assay represented a potential tool for the detection of Flu in fruit samples.